Included: Wheat staging and spraying limitations, cover crop selector, alfalfa management strategies, insect update, weed control concerns
Synopsis: Rainfall late last week until yesterday ranged from ¾” to 3” (20 to 75mm) slowing planting and putting others out of the field until at least the weekend. Corn planting ranges from 70% to over 95% complete: soybeans are in the 5% to 20% range. The window for weed control in wheat has virtually closed with most wheat at flag leaf stage: 50% to 80% of the crop was sprayed. Alfalfa weevil feeding damage is evident and getting close to threshold in some fields. The impact of the cold temperature from April 27 to 29 is visible on many of the emerged crops and had a significant impact on the fruit trees in the region.
Wheat: Wheat ranges from second node (32) to late boot stage (50). It is too late for weed control. Spraying now is for revenge or for harvest management, and late sprays can injure the crop. To stage wheat for spraying: squeeze the stem for the first node (the stem will crush, the node will not), squeeze above the first node to find the second node, and if the stem will crush above the second node and you feel a third node, then the flag leaf is emerging or fully emerged. If it is at flag leaf stage spraying for weed control comes with extra risk of crop injury: if you must spray for weeds use the safest possible products (Buctril M or Refine). Wheat that was sprayed during the cold week suffered significant leaf injury. There is very little disease in the crop, with only low amounts of powdery mildew. There have been questions about using a half rate of fungicide. Use the full rate! Where high rates of nitrogen have been applied two applications of fungicide can be considered, with current timing for the first application giving more yield increase than earlier applications would have.
Wheat tolerated the end of April freeze far better than expected. Temperatures of -5oC are critical level for wheat and many areas experienced -6 to -7oC. The warm temperatures in March and the rapid growth of the crop made it more susceptible to the frost in March. The cool temperatures in April may have made it more tolerant to the late April frost. If the crop has suffered frost damage the stem will stop growing. If you see a field that is not growing, go in and have a closer look. Yield potential of most fields remains excellent. Yield will be dependent on the weather at pollination and through grain fill.
Corn: Many growers have completed planting while a few have not started yet. Emergence looks very good, better than anticipated. A couple of good days will wrap up planting. Some slug feeding has been observed in the crop.
Soybeans: Early planted soybeans in the Harrow and Inwood (March!) area have emerged and look good. Soybean planting is just getting underway across the region. Monsanto planted soybeans near Chatham in March and on April 18th. The March soybeans are at the unifoliate to first trifoliate stage.
Other crops: Tomato planting has started with most growers planting full steam as soon as conditions permit. The sugarbeet crop looks good with early plantings at the four leaf stage. Limited replanting will be necessary. The wind and the frost had a greater impact on stands than crusting. Seed corn planting will begin soon. The separation in planting dates between grain corn and seed corn will minimize pollination issues. The potato crop is beginning to emerge. The fruit trees suffered significant injury from the frost and may only have 10-20% of a crop. Minor damage was reported to the grape crop.
Forage Crops: Some hay fields have been hit hard by the frost and disease. The new growth has been injured twice and as a result the crop is short. There are concerns regarding the impact on the crown and root reserves from having to restart growth. If it is a field that you want to keep consider letting it grow to flower to put some reserves back in the root and let it rest in the fall. If it is a field that is near the end of its useful life, try to get the most out of it. Alfalfa is not as frost tolerant as some crops. Orchard grass is very susceptible to frost. New alfalfa seedings are up 10 to 15% this year.
Cover Crop Selection Tool: Anne Verhallen with help from a team of Ontario specialists and researchers worked with the developer of the Midwest Cover Crop Council’s (MCCC) cover crops selector tool to create an Ontario version. The tool allows you to select your area, put in harvest date of the crop, field drainage information and the attributes you want in the cover crop (i.e. nitrogen source or scavenger, erosion control, forage value, interseeding, etc.). The tool will then provide a list of suitable species, timing for seeding, information related to the attributes and more. The MCCC website is http://www.mccc.msu.edu/ once there choose the cover crops selector from the menu on the left. Ontario information can be found in the OMAFRA Agronomy Guide and at http://bit.ly/omafracovercrops.
Insects: True army worm numbers reported from the U. S. are at normal levels. If you see cutworm feeding in corn please let Tom Cowan know tom.cowan@ontario.ca. There have been reports of bee deaths this spring. Tom is working with other ministries and agencies to determine the cause. A few aphids and cereal leaf beetles found in wheat crops, and alfalfa weevil in alfalfa, but nothing near threshold yet.
Weed Control: There is lots of weed pressure and the weeds are getting large. A burndown should be sprayed soon. Of concern is spreading atriplex because if it escapes the burndown there are no good options for control. Suspect glyphosate resistantCanada fleabane has been found in theNiagara area, and suspect giant ragweed in Napanee. This drives home the point that when spraying glyphosate you need to include other modes of action.
Sulphur: Peter is conducting sulphur research on winter wheat. He is currently not seeing a response in the replicated trials. If you know of strips where there is a visual difference from a sulphur application please let Peter know (peter.johnson@ontario.ca). Soybeans have not shown a response to sulphur so no need to apply sulphur to the crop.
Crop Insurance deadlines:
June 15: Last day to report unseeded acreage.
June 30: Spring seeded final acreage reports due.
July 10: Premiums due.
Publications:
Publication 812 – Field Crop Protection Guide is available at any resource center, or by calling ServiceOntario Publications, 1-800-668-9938 or 416-326-5300.
CropLine – 1-888-449-0937
CropPest Website – http://www.omafra.gov.on.ca/english/crops/field/news/news_croppest.html
Crop Technology Contacts:
Adam Hayes, 519-674-1621 adam.hayes@ontario.ca
Peter Johnson, 519-271-8180 peter.johnson@ontario.ca
Albert Tenuta, 519-674-1617 albert.tenuta@ontario.ca